This is a continuation of work on the epidemiology of diabetes mellitus (DM) and its complications among Hispanic and Anglo persons in 2 southern Colorado counties, in the San Luis Valley. We will continue this work because of the excess risk of diabetes among Hispanics, and the likelihood that they provide a unique population for the study of genetic and environmental factors as they interact to alter the risk of diabetes and its complications. We propose a two part study design. First, we will enhance the existing prevalent case-control study with 2 additional years of incident cases. This will allow the examination of risk factors for DM and vascular complications using an incident case-control design. Second, we will follow all groups examined at baseline prospectively for the development of DM and vascular disease. Persons with impaired glucose tolerance (IGT) will be followed at shorter intervals to assess the impact of changes in risk factors on DM incidence. This project will 1) provide a population-based description of NIDDM and its complications, 2) allow comparison of the prevalence and relationships of diabetic and cardiovascular risk factors in Hispanics and Anglos; 3) test the hypothesis that increased Amerindian admixture explains the excess risk of DM in Hispanics compared to controls, and examine the role of environmental risk factors as they interact with admixture; 4) estimate the incidence of DM and the role of risk factors in high risk persons with IGT; 5) continue the population-based survey of peripheral vascular disease using Doppler ultrasound techniques in this biethnic population; 6) estimate the incidence of vascular complications prospectively; 7) replicate specified genetic marker-DM associations; 8) validate reported family history of DM to determine its accuracy; and 9) attempt to characterize long-term glucose control in a population and relate it to the complications of DM observed prospectively.